Fog on Car Windows only in Certain Areas

My dad parks his car in the driveway overnight and I park my car in the street under a large tree. Why is it that his car windows are covered in fog every morning and he has to defrost them, while the windows of my car have never had a drop on condensation on them?

There isn’t as much cooling under a tree because it’s already cooler. This is especially true if the driveway is concrete or, more extreme, blacktop. Fog/dew forms as the air cools and moisture condenses out of it.

 [b] Micro-climate.[/b]  The two spots likely have different air flows.  I would say the large tree is making the difference.  Trees like people breath.  During the day the leaves release moisture pulling more moisture up from the roots along with nutrients from the soil. It also could be that the driveway has more or less air motion.  

There are lots of possible issues.